Masonry Anchor Strength Design Guide 2024 design considerations section for helpful illustrations on understanding edge distances to hollow head joints and projected breakout failure areas .
The design example provided later in the guide will be based on fully grouted CMU construction .
UNGROUTED CMU CONSTRUCTION
Based on Section 3.4 of ICC-ES AC58 , the tension failure modes for adhesive anchors in ungrouted CMU construction are steel failure and pullout failure . The shear failure modes for adhesive anchors in ungrouted CMU construction are steel failure , anchorage failure , and masonry crushing failure . The corresponding equations are provided below :
Tension — Nominal Strengths
Nominal Strength Equation
CLAY BRICK CONSTRUCTION
Based on Section 3.6 of ICC-ES AC58 , the tension failure modes for adhesive anchors in clay brick construction are steel failure and pullout failure . The shear failure modes for adhesive anchors in clay brick construction are steel failure , anchorage failure , and brick crushing failure . The corresponding equations are provided below :
Tension — Nominal Strengths
Nominal Strength
Steel Strength
Pullout Strength
Equation
N sa
= A se , N ƒ uta
N k , br
Notes : N sa discussed on page 4 .
N k , br shall be taken from 3rd party evaluation report such as ICC-ES ESR or IAPMO UES ER .
Shear — Nominal Strengths
Steel Strength |
N sa
= A se , N ƒ uta
|
Nominal Strength |
Equation |
Pullout Strength
N k , ug
Notes : N sa discussed on page 4 .
N k , ug shall be taken from 3rd party evaluation report such as ICC-ES ESR or IAPMO UES ER .
Steel Strength
Anchorage Strength
V sa
= 0.6A se , V ƒ uta
V s , br
Shear — Nominal Strengths
Brick Crushing V mc , br = 1750 x 4 ƒ ́m
A se , V
Nominal Strength Steel Strength Anchorage Strength
Equation
V sa
= 0.6A se , V ƒ uta
V s , ug
Notes : V sa and V mc , br discussed on pages 5-6 .
V s , br shall be taken from 3rd party evaluation report such as ICC-ES ESR or IAPMO UES ER .
Masonry Crushing V mc , ug = 1750 x 4 ƒ ́m
A se , V
Notes : V sa and V mc , ug discussed on pages 5-6 .
V s , ug shall be taken from 3rd party evaluation report such as ICC-ES ESR or IAPMO UES ER .
PARTIALLY GROUTED CMU CONSTRUCTION
Based on Section 3.5 of ICC-ES AC01 and AC58 , the tension and shear failure modes for post-installed anchors located in the grouted cells of a partially grouted CMU construction will follow the same design provisions as fully grouted CMU construction based on Section 3.3 of ICC-ES AC01 and AC58 . However , the design in partially grouted CMU shall consider that the distance to the ungrouted cells is to be considered an edge for the purposes of design . The tension and shear failure modes for adhesive anchors located in the ungrouted cells of a partially grouted CMU construction will follow the same design provisions as ungrouted CMU construction based on Section 3.4 of ICC-ES AC58 . If the location of grouted cells is unknown , follow the same design provisions as ungrouted CMU construction based on Section 3.4 of ICC-ES AC58 .
Masonry Fastening Technical Guide Edition 24 Hilti , Inc . 1-800-879-8000 | en español 1-800-879-5000 | www . hilti . com | Hilti ( Canada ) Corporation | www . hilti . ca | 1-800-363-4458
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